Abstract
Although automated monitors for blood pressure (BP) measurement are used increasingly worldwide, understanding of how such devices are used in Brazil is low. This study analyzed the status of BP measurement by Brazilian health professionals. A questionnaire regarding experience with BP measurement was sent electronically to Brazilian nurses, nursing assistants, and doctors. It had 2004 responses. Previous experience with use of automated monitors was most frequent in men (71.2%), nursing technicians (65.5%), specialists (61.1%), secondary care (71.9%), emergency care (70.6%), or the private sector (66.3%). The least complied aspects of the standardized measurement protocol were availability of various cuff sizes (53.9% and 72.9% for auscultatory and oscillometric methods, respectively) and proper calibration checks (21.5% and 46.8% for auscultatory and oscillometric methods, respectively). Brazilian health professionals report not adequately performing all the necessary aspects to measure BP in accordance with the standardized protocol in both methods, but mainly regarding the oscillometric.
Keywords: blood pressure, blood pressure determination, blood pressure monitoring, blood pressure monitors
1. INTRODUCTION
Blood pressure (BP) measurement is a critical component of screening, diagnosing, and managing hypertension. The accuracy of BP readings depends on the measurement technique, the type of device used, and patient‐ and measurer‐related factors. 1
Simultaneous, blinded, two‐observer auscultation using mercury sphygmomanometers is considered the gold standard for measuring BP, but is impractical for clinical use. 2 Therefore, automated devices for BP measurement are increasingly used to diagnose and monitor patients with or without arterial hypertension. 3 The advantages of automated monitors over auscultatory instruments include practicality, availability of preprogrammed measurements, less noise interference, reduced risk of observer error, and the ability to take many out‐of‐office measurements enabling greater risk prediction and self‐monitoring. 4
International Society of Hypertension Global Hypertension Practice Guidelines 5 endorse the use of validated automated monitors for BP measurement, whereas the current Brazilian guidelines 6 offer no indication or contraindication for their use, complementarily or substitutively to the auscultatory method.
Given the importance of obtaining accurate BP measurements and the absence of formal recommendations for using the automated technique in Brazil, this study aimed to analyze the status of BP measurement by Brazilian health professionals, focusing on the use of automated monitors.
2. METHODS
This cross‐sectional study was conducted through an online survey. A questionnaire, hosted on SurveyMonkey®, was emailed to nurses, nursing assistants, and doctors to gather data on respondents' sociodemographic and professional information, experience with measuring BP using auscultatory and oscillometric methods, perceptions of the quality of BP equipment available in public and private health services, and adherence with the standard procedure.
The inclusion criteria were as follows: working in nursing or medicine, to have at least 6 months of professional experience, and to reside in Brazil. The invitation to participate was sent by email. Before the participants could access the questionnaire, they had to read and agree to the Free and Informed Consent Term. The questionnaire remained available for completion between August 2018 and February 2020. The study was approved by the Federal University of Ceara Research Ethics Board.
Data were extracted from the SurveyMonkey® platform in the Microsoft Excel® spreadsheet format. Duplicate files were excluded. Statistical analyses were performed by Stata 15.0 software. Pearson's chi‐square test was used to assess association between the variables.
3. RESULTS
A total of 2004 individuals participated in the study. The response rate was 12.7%. More than 97% of the study sample belonged to the nursing workforce, 55% were 35 years old or younger, 27% worked in tertiary care, and over 68% in the public sector.
Experience with automated BP monitors was most frequent in men (71.2%), in the South (65%) and Midwest (64.3%), nursing technicians (65.5%), doctors (65.3%), specialists (61.1%), ages 25‐45 years, secondary care (71.9%) and emergency care (70.6%), and the private sector (66.3%). There was an association between these variables and experience with automated BP monitors (P < .01), except for profession and work sector variables (Table 1).
TABLE 1.
Sociodemographic data and experience with automated BP monitors (N = 2004)
| Characteristic | No. (%) | Experience with automated monitors (%) | No experience with automated monitors (%) | P value a |
|---|---|---|---|---|
| Sex | ||||
| Female | 1655 (83.2) | 59.6 | 40.3 | <.01 |
| Male | 333 (16.6) | 71.2 | 28.7 | |
| Region | ||||
| North | 34 (1.7) | 55.8 | 44.1 | <.01 |
| Northeast | 336 (16.7) | 48.1 | 51.8 | |
| South | 1.171 (58.4) | 65.0 | 34.9 | |
| Southeast | 225 (11.2) | 61.8 | 38.1 | |
| Midwest | 238 (11.8) | 64.3 | 35.6 | |
| Occupation | ||||
| Nurse | 1.361 (67.9) | 59.8 | 40.1 | .05 |
| Nursing technician | 593 (29.5) | 65.5 | 34.4 | |
| Doctor | 50 (2.5) | 65.3 | 34.6 | |
| Graduation | ||||
| Specialization | 943 (47.0) | 61.1 | 38.8 | .66 |
| Masters | 392 (19.5) | 54.7 | 45.2 | .01 |
| Doctorate | 317 (15.8) | 49.5 | 50.4 | <.01 |
| Age | ||||
| Up to 25 | 219 (10.9) | 62.3 | 37.6 | .224 |
| 26‐35 | 884 (44.1) | 62.7 | 37.2 | |
| 36‐45 | 560 (27.9) | 62.1 | 37.8 | |
| 46‐55 | 248 (12.3) | 59.3 | 40.6 | |
| Older than 55 | 84 (4.1) | 53.0 | 46.9 | |
| Workplace | ||||
| Primary care | 451 (22.6) | 61.6 | 38.3 | <.01 |
| Secondary care | 215 (10.8) | 71.9 | 28.0 | |
| Tertiary care | 542 (27.2) | 66.6 | 33.4 | |
| University | 333 (16.7) | 49.2 | 50.7 | |
| Emergency care | 111 (5.5) | 70.6 | 29.3 | |
| Others | 338 (16.9) | 57.1 | 42.8 | |
| Workplace sector | ||||
| Public | 1.370 (68.3) | 59.9 | 40.1 | .01 |
| Private | 587 (29.2) | 66.3 | 33.6 | |
Pearson's chi‐squared test was used in the case of categorical outcomes.
Nearly 20% of workplaces did not have oscillometric equipment. Auscultatory equipment was rated as being in good condition 22.5% of the time and oscillometric equipment, 18.1% of the time.
For both methods, the least complied aspects of the standardized measurement protocol the availability of many cuff sizes (53.9% and 72.9%, for auscultatory and oscillometric methods, respectively) and proper calibration checks (21.5% and 46.8% for auscultatory and oscillometric devices, respectively). Respondents indicated that non‐adherence with all components of recommended measurement technique was higher when using the automated measurement methods (Table 2).
TABLE 2.
Adherence with the standardized protocol for measuring blood pressure using the auscultatory method and the oscillometric method (N = 2004)
| Protocol component | No. (%) with non‐adherence | P value |
|---|---|---|
| Suitability of the cuff to the brachial circumference | ||
| Auscultatory method | 305 (17.5) | <.01 |
| Oscillometric method | 471 (27.1) | |
| Availability of various cuff sizes | ||
| Auscultatory method | 936 (53.9) | <.01 |
| Oscillometric method | 1.265 (72.9) | |
| Checked for proper calibration | ||
| Auscultatory method | 373 (21.5) | <.01 |
| Oscillometric method | 812 (46.8) | |
| Patient positioning | ||
| Auscultatory method | 283 (16.3) | <.01 |
| Oscillometric method | 337 (19.4) | |
| Patient rest | ||
| Auscultatory method | 373 (21.5) | <.01 |
| Oscillometric method | 487 (28.0) | |
Pearson's chi‐squared test was used in the case of categorical outcomes.
4. DISCUSSION
The results indicate that Brazilian health professionals report that they lack experience in using automated monitors, which are not often maintained properly, and frequently do not comply with best measurement practices. Health professionals working in the North and Northeast, nursing, primary care, educational institutions, and the public sector, or with training at the doctoral level, had the least experience with automated BP monitors.
The differences in experience suggest that there are regional and education‐level inequities in training and the availability of BP monitors. Areas with historically greatest educational inequality in the country, 7 the North and Northeast, may have professionals who are less qualified to use automated BP monitors due to limited knowledge and training on this matter.
The most critical component for measuring BP is the individual responsible for the procedure. 8 The low level of experience in using automated monitors observed among teachers and professionals with high academic training, compared with those working in clinics and with lower academic degrees, continues the cycle in which new health professionals do not receive adequate training on new technologies that may improve BP measurement. This issue is critical in low‐resource settings, which may not be ideal for performing auscultatory measurement if they do not have quiet rooms, calibrate aneroid gauges twice a year, or continue training.
Measurement accuracy also depends on the adequacy of the equipment, the environment, and the patient. 9 Defects in the calibration have been reported as one of the most important causes of errors in BP measurement and, although it is not clear how often automated devices lose calibration over time, it is nevertheless important for devices used in health care settings to be checked periodically to ensure that readings are accurate. 10 This study found that the calibration status is not usually checked and that this lapse occurs more frequently with automated monitors than with manual mercury or aneroid sphygmomanometers. The study also showed that little of the measuring equipment is in good condition without broken or missing parts. The incipient maintenance of equipment and the lack of calibration raise concerns about the quality of BP measurement in Brazil, using either method.
The use of cuff sizes appropriate for each patient's arm circumference was common with the manual auscultatory method. However, approximately a quarter of the respondents admitted that they do not check whether the cuff is appropriate for the patient when using automated monitors. This represents a major problem, since under‐ or over‐estimation of BP values can result in inappropriate treatment and inefficient care to control arterial hypertension. 11
This result is consistent with a study that identified that Brazilian health units usually have only standard size cuffs, which is appropriate for only 17.3% of their patients. 12
The present study found that this problem is even more frequent when BP measurement is performed with automated devices. Automated BP monitors can be used at home or in clinics as well as by services with limited resources. 13 Devices for home use usually have a so‐called universal cuff, with adequate length and width for a wide range of brachial circumference sizes, although we note that in for many automated devices these “wide range” cuffs have been incompletely evaluated in validation studies. 14 However, monitors for clinical use are marketed with a variety of cuff size options.
Automated monitors for home use are more widely available in Brazilian health services than are monitors for clinical use. This situation probably influences health professionals' non‐adherence with recommendations on the use of adequate cuff sizes because these home devices are being used with a standard cuff size and additional sized cuffs are not procured. The low level of experience with automated monitors, uncovered in this study, corroborates this hypothesis and highlights the lack of knowledge about the functionalities of the different BP monitors currently commercialized in the country.
More than a quarter of the participants reported not paying attention to maintaining the patient's rest before measuring BP in the oscillometric method. It is essential to promote theoretical and practical BP measurement training as common errors in the procedure can lead to inaccurate estimations; for instance, professionals should not talk to the patient during the procedure, adopt a terminal digit, or use inappropriate or defective instruments. 9
The expansion of the use of automated devices to measure BP and the progressive replacement of auscultatory instruments with electronic technology reinforces the need to prioritize monitors that have been approved through formal clinical validations. 13 Although automated devices are not yet available in many health services in Brazil, the use of validated monitors needs to be reinforced. It is also essential to expand the available knowledge about oscillometric methods and promote adherence with the standardized BP measurement protocol to improve the quality of BP measurement in Brazil.
The study has limitations. The response rate was low, and the data were based on reports from participants rather than through direct observation. Nevertheless, the study's findings provide an overview of BP measurement in Brazil, which is novel. The study points out the greatest deficits, which may lead to the design of strategies to improve training and the quality of BP measurements obtained in the country.
5. CONCLUSIONS
Brazilian health professionals report that BP measurements have deficits in both methods, but mainly in the oscillometric method. The quality of the equipment used for auscultatory and oscillometric measurement is insufficient, and Brazilian health professionals do not adequately check all the necessary aspects to measure BP according to the standardized protocol. Mostly when using automated monitors, they do not adequately verify the appropriateness of the cuff size, the calibration status, and the patient's rest level and positioning.
CONFLICT OF INTEREST
The authors declare no conflict of interest.
AUTHOR CONTRIBUTIONS
Nila L. S. Albuquerque substantially contributed to the conception of the project, the acquisition, analysis and interpretation of the data, and the drafting and reviewing the manuscript. Raj Padwal aided in interpreting the results, contributed for important intellectual content, and critically reviewed the manuscript. Thelma L. Araujo supervised the work, contributed to the data collection, and critically reviewed the manuscript. All authors read and approved the final version of the manuscript.
Albuquerque NLS, Padwal R, Araujo TL. Overview of blood pressure measurement by Brazilian health professionals. J Clin Hypertens. 2020;22:1941–1944. 10.1111/jch.14010
Funding information
The study was supported by the Brazilian Ministry of Science and Technology (CNPq National Research Council) and the Coordination for the Improvement of Higher Education Personnel (CAPES).
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